National Security Agency Director Mike Rogers testifies before the U.S. Senate Select Committee on Intelligence on Capitol Hill in Washington, U.S. May 11, 2017. REUTERS/Eric Thayer

WASHINGTON (Reuters) - A top U.S. intelligence official said Thursday a controversial surveillance law that allows the broad electronic spying of foreigners played a major role in understanding Russia’s alleged interference in the 2016 presidential election.

The statement from Admiral Mike Rogers, the director of the U.S. National Security Agency, may bolster efforts by intelligence agencies to fully preserve the authority, known as Section 702 of the Foreign Intelligence Surveillance Act, before it expires at the end of the year.

Privacy advocates have for years said Section 702 allows for excessively broad surveillance, including warrantless access to some American communications, and should be reformed to include new curbs.

“I would highlight much, not all, much of what was in the intelligence community’s assessment, for example, on the Russian efforts against the U.S. election process in 2016, was informed by knowledge we gained through (Section) 702 authority,” Rogers said.

Rogers said allowing the statute to expire on Dec. 31, unless Congress votes to reauthorize it, would degrade U.S. intelligence agencies’ ability to provide “timely warning and insight” on a variety of criminal and national security threats.

U.S. intelligence agencies concluded that the Russian government orchestrated the hacks and disclosure of Democratic emails during the election in order to support Republican President Donald Trump and discredit his Democratic foe, Hillary Clinton. Russia has denied the allegations.

Section 702 allows the U.S. to spy on foreigners believed to be living overseas whose communications pass through American phone or internet providers.

For a variety of technical reasons, it also incidentally collects an unknown amount of data belonging to Americans, a practice that privacy advocates have said evades Constitutional protections against warrantless searches.

The law gained renewed attention following the 2013 disclosure by former intelligence contractor, Edward Snowden, that the agency carried out widespread monitoring of emails and other electronic communications.

A bipartisan coalition of lawmakers in the U.S. House of Representatives is working on legislation that would renew Section 702 but with new reforms, but it remains unclear if it would have enough support to pass Congress and be signed by President Donald Trump. A White House official told Reuters in March it did not want to alter the law.

Last month, the NSA announced it had stopped a form of surveillance under Section 702 that allowed it to warrantlessly collect communications of Americans who mentioned a foreign intelligence target in their messages.